For instance, a white oak and a bur oak grow near enough for the wind to "cross-fertilize" their pistillate flowers.
Professor Lake: I can't see any reason, but that if there are present any of the native trees, they are bound to cross-fertilize.
The fertilization that occurs when the nucleus of a male sex cell from one individual joins with the nucleus of a female sex cell from another individual. In plants, cross-pollination is an example of cross-fertilization. Also called allogamy. Compare self-fertilization.